En ny fototransistor för detektering av enstaka molekyler i elektrolyter

Tidsperiod: 2019-01-01 till 2022-12-31

Projektledare: Shi-Li Zhang

Finansiär: Vetenskapsrådet

Bidragstyp: Projektbidrag

Budget: 3 930 000 SEK

This project explores a novel phototransistor for its potential of single-molecule detection in electrolytes by exploiting the strengths while avoiding the pitfalls of optical and electrical sensor technologies. Its realisation can open up avenues to new applications presently unconceivable or unattainable. This phototransistor sensor concept exploits three distinct technologies. 1) MoS2-phototransistor of ultrahigh photoelectric efficiency and ultralow dark current thanks to the 1.8 eV large direct bandgap of MoS2. 2) Up-conversion (UC) of a near-infrared excitation to visible light of photons with energy matching the MoS2 bandgap, thereby triggering off the phototransistor with minimum interference. 3) Förster resonant energy transfer (FRET) from donor- to acceptor-molecule so as to facilitate high-specificity detection of biomolecules using the MoS2-phototransistor. A MoS2-phototransistor operated in electrolytes is essentially an ion-sensitive field-effect transistor (ISFET). As the input signal for this new ISFET is of optical nature, its application can be greatly expanded because the Debye screening effect disabling electrical sensing becomes irrelevant. Our recent success in demonstrating, for the first time, MoS2-phototransistor as an UC-enabled photodetector and the literature-reported detection of molecular binding based on the UC-FRET combination prompt this proposal. As proofs of concept, detection of biotin-avidin binding and DNA hybridisation will be performed.